FACILE SOL–GEL SYNTHESIS OF Li[Li0.2Mn0.56Ni0.16Co0.08]O2 AS IMPROVED CATHODE MATERIAL FOR LITHIUM-ION BATTERIES

Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 cathode materials for Li -ion batteries were synthesized by a facile sol–gel method followed by calcination at various temperatures (700°C, 800°C and 900°C). Lithium acetate dihydrate, manganese (II) acetate tetrahydrate, nickel (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate are employed as the metal precursors, and citric acid monohydrate as the chelating agent. For the obtained Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 materials, the metal components existed in the form of Mn 4+, Ni 2+ and Co 3+, and their molar ratio was in good agreement with 0.56 : 0.16 : 0.08. The calcination temperature played an important role in the particle size, crystallinity and further electrochemical properties of the cathode materials. The Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 material calcined at 800°C for 6 h showed the best electrochemical performances. Its discharge specific capacities cycled at 0.1 C, 0.5 C, 1 C and 2 C rates were 266.0 mAh g−1, 243.1 mAh g−1, 218.2 mAh g−1 and 192.9 mAh g−1, respectively. When recovered to 0.1 C rate, the discharge specific capacity was 260.2 mAh g−1 and the capacity loss is only 2.2%. This work demonstrates that the sol–gel method is a facile route to prepare high performance Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 cathode materials for Li -ion batteries.